# [−][src]Function mynewt::kernel::os::os_mbuf_prepend_pullup

    pub unsafe extern "C" fn os_mbuf_prepend_pullup(
        om: *mut os_mbuf,
        len: u16
    ) -> *mut os_mbuf

Prepends a chunk of empty data to the specified mbuf chain and ensures the chunk is contiguous. If either operation fails, the specified mbuf chain is freed and NULL is returned.

- `om`: The mbuf chain to prepend to.
- `len`: The number of bytes to prepend and pullup.

Return: The modified mbuf on success; NULL on failure (and the mbuf chain is freed).

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